Weight is a covariate representative of body size and is known to influence drug disposition. Recently, with increased use of allometric scaling, this variable has become more significant in accounting for variability in pharmacokinetic parameters. In adults, weight can be considered as a time invariant covariate because physical development is complete. As a result, when weight is missing in data, the typical or median value (say, 70 kg) could be imputed. On the contrary, weight continuously changes with age in the pediatric population. In this case, it is more appropriate to consider different median weight for each age group. We constructed a prediction model for weight using postmenstrual age (PMA) with the data consisting of 83,014 Korean pediatric patients. Weight, PMA, and gender information were collected from electronic medical records. Sigmoid models multiplied by exponential or logistic function were tested for basic model structure. Covariate effects on model parameters were then investigated using selection criteria of p < 0.001. All analyses were performed using NONMEM 7.3.0 and R3.2.0. The sigmoid model multiplied by logistic function best described the data and there was a significant difference between boys and girls in model parameters. It is expected that the results obtained in this work can be used for imputation of missing weights in pediatrics when PMA is available. In addition, the developed model can be used for clinical studies in children under 12 years old whose weight change rapidly with age and for model building in dealing with time varying body weight as a covariate.
Adult ; Body Size ; Body Weight* ; Child ; Colon, Sigmoid ; Electronic Health Records ; Female ; Humans ; Patient Selection ; Pediatrics ; Weights and Measures

Objectives: This study aimed to analyze the outcomes of the Comprehensive Health and Social Need Assessment (CHSNA) system, which identifies community residents’ health and social needs, and to link these needs with the International Classification of Functioning, Disability, and Health (ICF). Methods: Adult community residents in a metropolitan city in Korea were recruited. They were asked to assess their health and social needs via the CHSNA system, which was integrated into an online community-care platform. Three assessment steps (basic health assessment, needs for activities of daily living, and in-depth health assessment) associated with five ICF components were used to evaluate physical health impairment, difficulties in activities and participation, and environmental problems. The final list of health and social needs was systematically linked to the domains and categories of the ICF. Only data from participants who completed all three assessment steps were included. Results: Wide ranges of impairments and difficulties regarding the daily living activities, physical health, and environmental status of the community were recorded from 190 people who completed assessments of their health and social needs by the CHSNA system. These participants reported various health and social needs for their community life; common needs corresponded to the ICF components of body functions and activities/participation. Conclusions The ICF may be suitable for determining the health-related problems and needs of the general population. Possible improvements to the present system include providing support for completing all assessment steps and developing an ICF core set for an enhanced understanding of health and social needs.